Browsed byMonth: November 2010

Earthquake stats for the year so far have been pretty shaky indeed. As always, below is included an explanation of where averages come from. Below that you will find the statistics for the third quarter and the year totals so far. It’s been a very interesting year all the way around.

About The USGS and RHS1 Averages:

The USGS statistical averages are averages compiled from 1990 to 2000. That is when global tracking was achieved and we have no way of knowing for sure how accurately those statistics represent numbers before that time. There are scientists who did tracking, but there were also many very volatile areas that aren’t populated and it was impossible to track before. From old records we can assume that there have been more recently, but there is no way to know for sure.

We also use an RHS1 average which is 3 year statistical average which was drawn from my three year quake report from 2006, 07, 08 that I will compare the quarterly statistics to, so we can see a more current trend. At the end of this year we will add this year’s average to the three year average, making an average of 4 of 5 years since the middle of the current decade. If data can be retrieved for 2009, a year in which our site was being rebuilt from hacker/virus injection damage, we will add those in to make a current half decade statistical average.

8 Magnitude and Stronger:

We had none during the second or third quarter. We had one in the first quarter.

The USGS average is 1, if any per year. The RHS1 average is two per year.

We are holding steady at low average for these massive quakes.

7 Magnitude and Stronger:

We experienced a whopping 9 of these shakers this quarter bringing the year total in the third quarter up to 17 – which is the USGS yearly average for these massive quakes. RHS1 3 year average is 11 annually, a 35% drop from the USGS average. It looks like these are going to break both averages this year.

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6 Magnitude and Stronger:

We experienced 37 of these strong quakes in the third quarter. With only 29 of these quakes in the second quarter and a the high number of 48 during the first quarter, we have now experienced 114 mag 6 quakes already as of the end of the 3rd quarter. The USGS average is 134 per year. RHS1 average is 159 annual mag 6 quakes per year. Only 20 quakes in the forth quarter will see the USGS average but 45 still need to occur to reach the RHS1 average. It looks like we will be considering this year a high or a low according to which average you want to look at.

5 Magnitude and Stronger:

There were 401 of these quakes during the 3rd quarter of the year. We experienced only 285 of these strong shakers second quarter – but we had extremely high numbers the first quarter – 565 of them! At 1251 total for this year as of the end of the third quarter, we will exceed both averages this year. USGS average is 1319 per year. The RHS1 average is only 1275 per year. Judging from my recordings so far of the 4th quarter, we already have. The only question left is by how many we will be exceeding averages.

During the first few quarters of the year most quakes were happening at depths of 10 and 35 km, indicating a crustal shift was going on. In the third quarter there were still quakes occurring at these depths but not in such a profusion as earlier in the year. The depths are becoming disperse again with no real perceivable patterns to them.

The high number of quakes this year are mainly due to some strong and lengthy aftershocks occurring after the major 7 and 8 magnitude quakes experienced near the beginning of the year.

Finding a great agate or piece of jasper is a thrill for any rockhound, but being able to identify exactly what it is that has been found is quite a headache for the beginner. These headaches can be relieved very easily though with just a little bit of knowledge about the different quartz group stones.

Agate and jasper are actually chalcedony, which in turn is cryptocrystalline quartz. All are SIO2. When you pick up a stone you can rule out that it is a piece of regular massive quartz quite quickly just by looking to see if you can see the grains of the stone. If you can see grains, you do not have an agate or jasper. Most likely, what you have then is massive quartz or some other type of stone. Many new rockhounds will mistake massive quartz for a piece of agate, so don’t feel bad if you do. It’s a very frequent mistake.

Jasper and agate will appear to be made of wax. If the rock is just plain clear to white translucent with no markings or patterns, it is considered chalcedony. If it is opaque, that is, if you cannot see into or through it, it is jasper. Jasper is most frequently earth tones or red but you can find jasper in just about any color or color combination and it can contain some very lively patterns. One well known form of jasper is called “picture” jasper, and just as the name suggests, the lines and markings look just like a scenic picture of mountains and valleys or forests and so on. Geometric patterns are also common in jasper stones.

If a stone is an agate, it will be translucent as is chalcedony, but an agate will have patterns. Most commonly, agates have bands, and are appropriately called banded agate. Sometimes the bands are also translucent, sometimes some are opaque. There are many agates named to describe how they look, such as plume, orbicular, or flower and many that are named for the place they are found, such as Dryhead or Lake Superior. For instance, moss agate is a clear to semi-clear agate that looks like moss was embedded in the stone. No two agates are alike and many fantastically patterned stones will not have specific type or place names.

There are also stones which you will find that have both jasper and agate in them. Both the opaque and translucent parts of these stones will appear waxy. These are often referred to as jasp-agate. Once you become familiar with the look of both jasper and agate, you will be able to recognize jasp-agate with no problems. One other stone that can be confused with agate or jasper is opal.

Opal will have flashes of color if it is precious opal. It can be also be common opal which is plain translucent or opaque and a just about any color or a mix of colors. Opal generally looks more glassy than waxy, and it is much more brittle and breakable than agate or jasper.

If you still aren’t sure when you find a rock if it is jasper, agate, or opal, you should take it with you and ask someone about it. Your local rock shop or club or even a jeweler’s shop can identify it for you. You will have few problems identifying these stones after the first or second time. Once you learn to identify these basic stones, you will be surprised how many different types of gemstones you will start noticing on your hunts.